Xerox 8500DN Service Manual - Page 40

Theory of Operation Printhead Ink Loader Level Sense Probe Funnel Filter Black Yellow Purge Valve Ink Cyan Magenta s8500-013 The Printhead's jet stack is fabricated from a stack of chemically etched steel plates which are brazed together to form the jet array. Channels formed by the stacked plates route ink past the 1236 individual, piezo-electric crystal-driven diaphragms, which force the ink in droplets out the 1236 corresponding nozzles. Looking at the Printhead face, the nozzles are arranged in 12 rows, in color order KYKYKYCMCMCM, where K = black, Y = yellow, C = cyan, and M = magenta. During the printing process, the Printhead would only have to travel approximately 14 pixels horizontally to provide complete coverage. However, the Printhead travels much further, depending on print resolution, to interlace each jet with the output of neighboring jets. The jet array bonds to a cast aluminum ink reservoir, which supplies the molten ink to the jet array. Heaters in the reservoir and the jet array maintain the ink at a printing temperature of about 60 degrees centigrade. 2-8 Phaser 8400/8500/8550/8560 Color Printer Service Manual